1. Field of the Invention
The present invention relates to electronic circuitry. More specifically, the present invention relates to systems and methods for interconnecting circuit boards in a stack configuration.
2. Description of the Related Art
For certain applications, there is a need to provide high-density packaging of electronic circuitry in a small area. This need is often addressed by stacking multiple circuit boards. Signal transfer between boards is effected through z-axis linkage. ‘Z-axis linkage’ typically includes conductors embedded in a dielectric medium, restrained wire (“fuzz buttons”), and various contact schemes using flex cables including dimples, grooves and gold dots. Unfortunately, all of these schemes have limited applicability, some because of relatively high contact resistance and some because of the high pressure required to assure contact.
The prior art approaches generally require tight vertical spacing and tolerances which limit their application to highly controlled substrate flatness and via or target height control. In addition, the assembly of these connectors for static applications involves pressing the contact on the via or target without any wiping action which, in the case of any contamination on either surface or slight misalignment, can increase the contact resistance or, under worst case conditions, prevent an electrical connection.
Hence, there is a need in the art for a system and method for providing highly reliable, low cost z-axis interconnect between substrates in a three-dimensional stack of circuit boards.